Dashboard functionality of KDE comes to mind. (Ctrl-F12)
Icon only task manager available as an option in KDE.Most distros don't fold applications into icons on taskbar (aka Windows 7 style).
Modern versions of KDE, Gnome , Unity..etc all have search. (for kde, windows 7 like and for the other two windows 8 like)Some do not even have search functionality on start menu.
I only mention KDE because that is what I've been using for a few years.
But I'm sure any DE/WM with a sizeable userbase has those as some sort of option, application or plugin.